Solder resist applying machine

Abstract

A machine and a method for applying a solder resistant material or solder resist to predetermined portions of miniature connector structures are disclosed. The machine permits large numbers of the miniature connector structures to be precisely treated with the solder resist without the need for costly and time consuming masking procedures. More particularly, the miniature connector structures attached to a carrier strip are fed through a hybrid fluid dispensing assembly similar to a bath, which is continuously supplied with the solder resistant material. The quantity of material supplied to the hybrid fluid dispenser or bath is coordinated with the speed at which the miniature connector structures are driven through the bath so that each of the miniature structures absorbs a predetermined amount of solder resistant material by capillary action. The quantity of material absorbed by each of the miniature connector structures is controlled so that it is just sufficient to fill a desired area. The filled connectors are subsequently heated to cure the solder resistant material.

What is claimed is: 
     
       1. Apparatus for applying solder resistive fluid in discrete quantities to a plurality of serially arranged electrical contacts without a need for masking, comprising: a fluid reservoir containing a supply of fluid material,   dispensing means adjacent said reservoir for transferring discrete quantities of fluid material from said fluid reservoir to a plurality of electrical contacts serially transported to said dispensing means,   drive means for transporting said electrical contacts serially to said dispensing station,   fluid supply means for supplying fluid material to said reservoir, thereby replenishing the discrete quantities of fluid transferred to said electrical contacts, and   adjustable flow regulating means for controlling the rate at which fluid is replenished from said fluid supply means to said reservoir,   said dispensing means including a fluid dispensing elongated channel along which said electrical contacts are transported by said drive means,   said dispensing means being filled with said fluid material and forming an elongated droplet of fluid material which is lengthwise of said channel and which is raised outwardly of said channel by fluid surface tension,   one lengthwise side of said channel having means operatively associated therewith for biasing said elongated droplet transversely whereby to impinge said contacts transported serially along said channel.   
     
     
       2. The structure recited in claim 1, wherein, another lengthwise side of said channel provides means for supporting said contacts transported serially along said channel. 
     
     
       3. The structure as recited in claim 1, wherein, said drive means transports said contacts serially along said channel lengthwise thereof and into impingement with said droplet causing transfer of fluid in said droplet to said contacts. 
     
     
       4. The structure as recited in claim 1, and further including: a heat applying station whereat heat is applied to said contacts to dry said applied quantities of fluid, said drive means transporting said contacts serially from said dispensing station to said heat applying station.